🔗 Share this article

There's a nervous excitement. Apparent is the frosty air exhaled by my fellow runners as they perform the "pre-race" shuffle on the start line.

A swift twitch of the hips.

I'm participating in my local weekly parkrun event and I'm focused. It's almost time...

Hold on. I need to adjust my tracker. As does the guy next to me.

The person behind us sighs. I won't start until… done! Connection established, and I'm running.

During the scramble, it's challenging to find a wrist without a wearable on it. And it's not just us participants who rely on them.

It's a booming, massive market. Brands like Samsung Galaxy are prevalent, each with an extensive selection of different versions to cater to a variety of lifestyles. Based on how high tech the watch you select, price tags can range from a hundred pounds to a significant investment.

"I find it infuriating, I can't switch off."

"It reassures me… It's like a companion guiding me."

"Stop telling me I've experienced a bad night's sleep."

A small sample of the responses I've received from fellow tracker enthusiasts when I question what they their opinion is on theirs.

The Data Dilemma

My thoughts on mine? Right now, irritating. It's indicating I'm not hitting my target, making me wonder whether the foliage I'm running below are interfering with my GPS connection.

Countless individuals of us attach these small monitors onto our wrists and wear them all day and night, ostensibly comfortable with the fact they're continuously recording us.

Long past are the days when we relied on them exclusively to give us an idea of our pedometer reading. Currently, they can measure our nightly rest, blood pressure, oxygen saturation, our recovery score.

It's a challenge to find a health indicator they fail to monitor.

But can they do what they claim to do? And are the numbers we obsess over a faithful picture of reality? Do they boost our mental and physical wellbeing, or do the avalanche of measurements and constant notifications just contribute to our sense of overwhelm?

A Love-Hate Relationship

"I do get a quite preoccupied with mine," a wearer confesses.

While she loves how her device records her exercise, she finds some of its other capabilities "excessive" at times - a feeling that became apparent during a pregnancy.

Until she found out she could adjust the settings, her smartwatch kept telling her she was being insufficiently energetic enough. Now, the watch keeps telling her she's had a poor sleep score.

"I am caring for a six-month old, I don't need to be notified I've not slept," she says. "That fact is only too well."

Why doesn't she just take it off?

"I could, theoretically, but I've got this complicated dynamic with it," she says. "I love it for its exercise data, but I'm unsure whether the myriad other functions it can now do is possibly too much for me."

Inside the Device

Every device of smartwatch has its own unique way of monitoring your vitals and processing your data, but the vast bulk use optical sensors on the back of the watch.

They typically emit small, green LED lights onto your skin which can observe capillary action, detecting your BPM. More advanced devices measure changes in the electrical current that passes over the skin to gauge your nervous system activity.

The Professional Viewpoint

A data scientist says that overall for smartwatches, it's a "delicate equilibrium" - while the continuously improving tech could realistically prevent illness, "detecting disease before we show symptoms", it could also turn us device users into the "concerned but fine".

He points out that the most advanced wearables can carry out tests like electrocardiograms (ECGs), which constantly monitor how healthy the heart is. They can notify if someone is experiencing an irregular rhythm, where there is erratic electrical activity in the heart causing an irregular heartbeat.

This does not automatically signal someone is about to have a cardiac event, but it can give an preliminary indication they might be more at risk of a blood clot in the future.

But how to make sense of these readings is not straightforward. The expert concerns that as further capabilities are incorporated, people may find it hard to fully understand their data.

"I'm not entirely convinced that having the capacity to monitor so much data is such a positive development," he says.

A health researcher studying cardiology echoes this sentiment. A study into the effect of wearable tech on a cohort of heart condition patients suggested a noticeable percentage of those who were given devices to monitor their cardiac function experienced greater stress and were "had a higher tendency to use medical services".

She noted a pattern with her patients - they saw a alarming metric on their watch. They grew concerned. Their BPM increased. They got more worried. They looked a second time, and their reading went up again.

"When people are presented with stats about ourselves that we don't really understand then, of course, we are going to become concerned," the psychologist says. "We monitor, we re-check - it becomes a self-fulfilling prophecy."